How to sum all the numbers in a text file?

Question

I have to calculate the sum of any numbers in the file and print the sum.

A number is defined as any string beginning with a digit 0 through 9 followed by any numbe

Answer 1

I'd suggest that use RegEx:

import re

with open('file') as f:
    print(sum(int(i) for i in re.findall(r'\b\d+\b', f.read())))

In this case:

• \b+ match all the numbers, and \b checks if there a letter after (or before) the number so we can ignore abcd7 or 9kk.

• re.findall() try to find all the numbers in the file use the RegEx \b\d+\b and returns a list.

• A list compression, int(i) for i in re.findall(r'\b\d+\b'), convert all the elements in the list which returned by re.findall() to int object.

• sum() built-in function sums the elements of a list, and returns the result.

Online RegEx demo